1. Field of the Invention
The present invention relates to a storage medium storing a display control program used in providing stereoscopic display using two images on a display capable of providing stereoscopic display, a storage medium storing a library program, an information processing system, and a display control method.
2. Description of the Background Art
A method for providing stereoscopic display using two images having prescribed parallax has conventionally been known. Such stereoscopic display has increasing fields of applications. For example, applications for displaying a three-dimensional virtual space, such as a game and CG animation, have been developed.
In such an application, stereoscopic display is carried out by setting two virtual cameras within a three-dimensional virtual space and using images including a subject such as an object obtained by virtually photographing the subject with respective virtual cameras. For stereoscopic display easily viewable by a user, the two virtual cameras should appropriately be set. For example, Japanese Patent Laying-Open No. 2003-107603 discloses a method of generating images for stereoscopic display such that a portion to which attention is desirably paid is focused.
In generating an image expressing a three-dimensional virtual space including an object on a related display, in some cases, a technique for rendering various objects (a player character, a non-player character, a geographic feature object, and the like) and generating and processing an image displayed as a background of the object (an image expressing a perspective such as sky or clouds) independently of that rendering has been adopted. By adopting such a technique, advantageously, the number of man-hours required for development of a program can be decreased and processing for generating an image expressing a three-dimensional image space can be performed faster.
If the technique as above is adopted in carrying out stereoscopic display on the display as described above, however, problems as follows may arise. Namely, the first problem is that, for stereoscopic display of various objects, two virtual cameras should be set at respective appropriate positions within the three-dimensional virtual space and two images of an image for right eye and an image for left eye should be generated for an image to be displayed as a background. In designing processing for generating an image for stereoscopic display, a developer of application software should design the processing in consideration of more viewpoints than in the case of two-dimensional display. In addition, the second problem is that an image to be displayed as a background should visually be recognized as a picture located on the rearmost side when viewed from the user and hence the image to be displayed as the background should appropriately be generated/updated each time a degree of stereoscopic effect in stereoscopic display of the object is changed.
As described above, if the technique that has been used in two-dimensional display as described above is applied to stereoscopic display as it is, disadvantageously, an amount of processing required for display is excessively great.